Disc brake with pressure piece

ABSTRACT

A disc brake for a commercial vehicle, operated pneumatically or by electric motor, comprising a brake caliper, an application device and at least one adjuster device arranged with the brake caliper, is characterized in that both adjuster elements of the at least one adjuster device are fixed in a non-rotating manner to a common connector plate in the region thereof facing the brake lining and/or a single- or multi-piece thermal insulation layer is at least partly applied to the connector plate or parts connected thereto on the side thereof facing the relevant braking lining to form a region like a pressure piece.

BACKGROUND AND SUMMARY OF THE INVENTION

The present invention concerns a pneumatically and/or electromotivelyactuable disc brake.

Disc brakes are known, e.g. as sliding caliper disc brakes, swivelcaliper disc brakes, or fixed caliper disc brakes.

Sliding caliper disc brakes require a fixed-axis component or carriers,which carries the brake linings effective at one side of the disc brake,and which absorbs its peripheral force when the disc brake is activated,and also holds the caliper displaceably lodged in parallel to the axisof the vehicle. The relative movement, which the caliper performsagainst the fixed-axis component, can be divided into a power stroke andwear stroke.

To balance the wear of the brake lining and/or disc brake, at least oneadjustment device is arranged in the caliper, which acts upon the brakelining by means of one or two pressure pieces that are displaceableessentially axially to the disc brake, in order to adjust the distancebetween the brake lining and the brake disc.

If separate adjustment devices are arranged on both sides of the brakedisc, it is merely necessary to align the displacement path of the brakedisc in such a way that the release clearance can be overcome and theelastic deformation of the brake lining and the caliper, in other wordsthe power stroke, can be balanced out (see e.g. PCT/EP01/09366).

The adjustment devices provided on both sides of the disc brake consiste.g. of adjustment sleeves, which, as adjustment elements of an electricmotor or another mechanical device, are pivotable via a gear. Theseadjustment sleeves consist of an inside thread, into which a bolt-likespindle of the respectively thereto arranged pressure piece is screwed,so that with appropriate rotation, a relative axial movement is providedbetween the adjustment sleeves and the pressure pieces. Also known is areverse arrangement, in which the pressure pieces have a sleeve-likespindle, which is pivotable on a bolt that forms the adjustment element.

The brake lining material is directly connected to the lining support,which in turn is either connected with the pressure piece, or restsagainst the pressure piece “loosely” without connection.

From German Patent document DE 42 30 005 A1, a disc brake with a slidingcaliper is known, in which on each side of the disc brake, two pressurepieces arranged next to one another each act on a lining support of abrake lining, which is equipped with a lining support material.

A disadvantage of these known constructions lies in the fact that thefrictional heat that is generated during a braking action is conductedthrough all components of the adjustment device without any blockage,whereby the downstream functional elements are exposed to a specialstress, which reduces the service life. This is especially of concernwhen electric motors are employed as drive units for the adjustmentdevices.

Since disc brakes, which are utilized in utility or commercial vehicles,are subjected to the highest stresses, this issue is of particularsignificance, especially in terms of economy, since a shortened servicelife, and consequently the replacement of the corresponding functionalelements, entails not only repair costs, but also costs that arise fromthe necessary out of service time of the utility vehicle.

From German Patent document DE 39 19 179, a disc brake is known, inwhich, at the side of the brake lining that faces the pressure piece, aninsulating board is mounted at the lining support, which reduces theflow of heat between the brake lining and the pressure piece. Since ahigh generation of heat at the brake disc and the brake linings isobtained with braking, the insulating board protects the inside of thecaliper—that is the brake application unit and the adjustmentdevice—against overheating. The problem can be minimized by means ofthis solution.

It is also necessary to keep the pressure pieces and the adjustmentelements torsion-resistant, in order to achieve, in conjunction withstationary, yet pivotable corresponding elements, such as adjustmentsleeves with an inside thread, in which the adjustment elements areprovided as a thread spindle, an axial movement of the thrust pieces.

The present invention is, therefore, based on the objective of furtherdeveloping a disc brake of the above-mentioned type such that, withconstructively minor measures, on the one hand during braking actions areduced heat conduction into the inside of the caliper, and/or aconstructively simple method for securing torsion-resistance of theadjustment elements and their corresponding elements, is achieved.

This objective is attained with a pneumatically and/or electromotivelyactuable disc brake for a utility vehicle, having a caliper thatstraddles a disc brake, at least one brake application unit arranged inthe caliper for clamping the disc brake, and at least one adjustmentdevice arranged in the caliper to offset brake lining wear, and/or brakedisc wear by adjusting a distance between at least one brake lining, andthe brake disc, which consists of two axially displaceable adjustmentelements, each with a pressure piece, wherein the two adjustmentelements of the at least one adjustment device are fixedtorsion-resistantly in their areas that face the respective brake liningat a common connection plate, and/or at the connection plate, and/or atthe pressure piece on the side facing the respective brake lining, asingle- or multi-part heat-insulting layer is attached at leastsection-wise.

Accordingly, the two adjustment elements of the at least one singleadjustment device, are attached torsion-resistantly in their area facingtheir respective brake lining, on a common connection plate; and/or atthe connection plate, and/or at the pressure piece on the side facingthe respective brake lining a one-part or multi-part heat-insulatinglayer(s) is/are attached at least in sections.

As compared with the state of the art, this connection plate in itsfunction as securing torsion-resistance offers not only substantialadvantages as far as production and assembly are concerned, due to itssimple construction, but also functional advantages, since theconnection plate always remains at the same position on the pressurepieces, i.e. the connection plate moves according to the axialdisplacement of the pressure pieces along with them.

Thereby, in addition to the constructively uncomplicated securing oftorsion-resistance of the pressure pieces, a protection of thedownstream functional components from the effects of heat is alsoeffectively enabled via simple means; this is achieved on the one handby the connection plate itself, and on the other hand by the layer onthis plate, or at the pressure piece.

Thereby, strain caused by the excessive heating of the parts arranged inthe inside of the caliper, or an impairment of their ability to functionduring continuous or frequent heating with the resulting issuesdescribed in the state of the art, are prevented.

Preferably, the connection plate is realized as a thermal shield, whichis dimensioned in such a way that it covers the opening of aninstallation space in the caliper, in which the adjustment device isplaced, covered to a large extent. In addition, the opening may beclosed by a further cover plate, which is screwed in at the opening ofthe caliper, and therefore is not axially displaceable, and hasbreakthroughs for the thrust elements.

It is extremely advantageous if the heat-insulating layer is realized inone part or several parts, and is directly mounted onto the connectionplate. The layer may consist of one or two ceramic plates, whichprotrude over the pressure piece beyond its largest diameter dimension,wherein this ceramic plate is mounted on the connection plate, which isconnected form flush and/or force flush with the pressure pieces, andwhich functions as heat protection, and as a device for securingtorsion-resistance for the two pressure pieces of an adjustment device.

According to a further preferred modification, a pressure piece thatforms the thrust piece plate is positioned upon the connection plate,and supports the heat-insulating layer. It is also contemplated,however, to place a ceramic layer on the pressure piece plate. In thismanner, the connection plate is clamped by the pressure piece plate.

Preferably, the pressure piece plate is held at the connection plateform flush in an axial direction and torsion-resistant.

Especially preferably, the pressure piece plate has recesses that facethe connection plate, which are contact-free in the material.

According to a further advantageous modification, the connector plate,in turn, has protuberances in the connection area with the adjustmentelements facing the brake lining, in which protuberances the adjustmentelements are appointed in a simple manner axially, andtorsion-resistantly.

It is thus a further advantage for the cylinder-shaped protuberance tohave stop notches formed in its surface area, which are realized in theinterior of the protuberance in the form of catch grooves, and which onthe outside correspond to catch grooves on the pressure piece plate, andon the inside correspond to noses of the adjustment element, and thusespecially allow for a simple assembly of these constructional elements.

According to a further modification, the area embedded in theprotuberance of the adjustment element has on its surface side slotsthat break through the material. In order to achieve optimized heatinsulation, the pressure piece plate may also be provided withbreakthroughs, which are, for example, arranged next to one another in aradial direction, and which effect heat insulation in this area. In eachof these cases, the pressure piece plate and the pressure piece areconnected torsion-resistantly to the connector plate.

In addition, expansion bellows may be connected at the connector plate,covering the respective adjustment elements as protection.

According to a further—also to be considered separately—modification ofthe invention, the pressure pieces and the lining support are eachconnected to one another in such a way that—continuously and in a simpleway—a retraction of the brake lining is guaranteed, when the adjustmentelements are turned back and when the brake is released.

With respect to the construction, it is a special advantage if, at thepressure piece, or at a component of the adjustment element connectedwith this, one or several plate springs are arranged, which undercut arod in a recess of the lining support. As an alternative, one or moreplate springs may be arranged at the lining support, which undercut thepressure piece or a component of the adjustment element connected to it.

Further advantageous embodiments of the invention are described andclaimed herein.

Exemplary embodiments of the invention are described in the following byway of the enclosed drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of the disc brake in a sectional sideview;

FIG. 2 is a partial section of a top view of the disc brake;

FIG. 3 is a detail view of the disc brake in a frontal view;

FIG. 4 is the detail view according to FIG. 3 in a plan view;

FIG. 5 is a cross-section through the detail view according to FIG. 3along the line V-V in FIG. 3;

FIG. 6 is a further exemplary embodiment of details of a disc brake ofthe invention in an exploded view;

FIG. 7 is a cross-section through the detail according to FIG. 6 alongthe line VII-VII in FIG. 6; and

FIG. 8 is a cross-section through a caliper section of a further discbrake.

DETAILED DESCRIPTION OF THE DRAWINGS

In FIGS. 1 and 2, a pneumatically actuable disc brake is shown, whichhas a caliper 1 in the form of a fixed caliper, which straddles an upperperipheral area of a brake disc 2. Contemplated, yet not shown, is alsoan electromotively actuated disc brake.

On both sides of the brake disc 2, brake linings 3, 4 are arrangedfacing in the direction of the brake disc, i.e., perpendicular to itsplane, which, as is customary, consist of a lining support plate 3 a, 4a, and lining material 3 b, 4 b applied thereon.

The caliper 1 in FIG. 1, in its right lower section 21, which extends inthe direction of an axle (not shown), is attached at an axle flange 22of the disc brake.

Here, the brake disc 2 is embodied by way of example as a brake disc,which is displaceable relative to the caliper 1 on the axle by theamount of the power stroke to be overcome during braking actions. As analternative, or in addition, the caliper 1 may also be displaceably orpivotably arranged. It is furthermore contemplated for the caliper 1and/or the brake disc 2 to be realized as elastically deformable in onepart of the path of the power stroke.

Since a relative movability is given between the caliper 1 and the brakedisc 2, which essentially corresponds to the amount of the power stroke,an adjustment system 5, 6 is provided. This consists of adjustmentdevices 7, 8 on both sides of the disc brake 2, to balance the releaseclearance or the brake lining wear resulting from the braking action.

The adjustment devices 7, 8 consist here on each side of the disc brake2, by way of example, of at least one or more, preferably two,adjustment sleeves 19, 20, in which bolt-like spindles 38, 39 ofpressure pieces 11, 12, functioning as adjustment elements 9, 10, arecarried pivotably in such a way that a relative axial displacement isprovided between the adjustment sleeves 19, 20 and the pressure pieces11, 12.

Of course, an opposite arrangement is contemplated as well, wherein theone- or multi-part pressure pieces 11, 12 have a sleeve-like shape 40,41, in which a bolt, onto which a gear of the adjustment drive acts viaan electric motor M, is carried pivotably. Such a sleeve-likerealization of the adjustment elements 9, 10 can be seen in FIGS. 5 and7.

The adjustment device 7 shown in FIG. 1 on the right side, is supportedby a pivot lever 23 arranged next to it and pertaining to the brakeapplication unit, which in its upper section is actuable by a piston rod24 of a brake cylinder 25, and which in its lower section is borne, forexample, by ball elements or by another bearing (not shown) at thecaliper, and which on its side facing away from the caliper is borne atthe adjustment sleeve 19 directly or via intermediate elements such asballs and/or other intermediate pieces.

The adjustment sleeve 20 arranged at the side of the brake disc 2opposite the pivot lever 23, is, however directly supported on theinside of the caliper.

As can be seen, especially when the features of FIGS. 1 and 3 arecombined, the two adjustment elements, which pertain to each respectiveadjustment system 5 or 6, and which extend in parallel to one anotherwith a spacing therebetween, and which are movable in the direction ofthe brake disc 2 axially back and forth, are connected to one another onone side of the brake disc by a yoke-like connector plate 15 or 16,which may also be formed of sheet metal, in such a way that they areheld torsion-resistantly relative to one another.

On their side that faces the disc brake, the connector plates 15, 16 areeach, directly or indirectly, layered with a continuous, or only locallyapplied—e.g. realized in a circular form—heat-insulating layer 13, 14,which prevents the frictional heat that is created by the braking actionfrom being conducted to further, downstream functional components. Theconnector plates 15 and 16, working in conjunction with theheat-insulating layers 13, 14, e.g. made of ceramic, function here aspressure pieces 11, 12.

The connector plates 15, 16 serve, apart from the support and securingof the torsion-resistance of the adjustment devices 7, 8, also as aprotective shield for the functional components arranged behind them(e.g. the electric motor M) against heat radiation, since theycompletely or largely close openings realized in the caliper facing thebrake disc, as is schematically indicated in FIG. 1.

By the torsion-resistant attachment of the pressure pieces 11, 12, andtherefore of the adjustment elements 9,10, their joint axialdisplacement, and therefore a displacement of the brake linings 3, 4 ismade possible, whereby in the realization of the adjustment elements 9,10 the adjustment sleeve 19, 20 rotates as a threaded bolt, whereas ifthe adjustment elements 9, 10 are realized as a threaded sleeve, thecorrespondingly realized bolt can rotate therein.

In FIGS. 3-5, an exemplary embodiment of the connector plate 15 with athereto connected or positioned heat-insulating layer, in either case intwo parts, is shown. The layer 13 forms the actual pressure contactsurface against the brake lining.

As is especially represented in FIG. 3, the connector plate 15 is formedand dimensioned such that it largely covers the front side of a seat ofthe caliper 1 (FIG. 1), in which the respective adjustment system 5, 6is positioned.

In the exemplary embodiment according to FIGS. 3 and 5, theheat-insulating layer 13 consists of two plates or discs, for examplemade of a ceramic, which are embedded in the connector plate 15, and areattached therein.

To protect against dirt and debris, the pressure piece 11 is covered upto an area that partially covers the adjustment element 9, by means ofan expansion bellows 17, which, on the side facing away from theheat-insulating layer 13 of the connector plate 15, is attached thereto.

The expansion bellows 17 is, hereby, attached at its side that faces theconnector plate 15 to an inner collar 45 on the pressure element 9, andto an outer collar 46 on the connector plate 15, which allows for theassembly, and the balancing out of radial movement between thesecomponents.

A further exemplary embodiment of the invention is shown in FIGS. 6 and7.

Herein, the sheet metal-like realized connector plate 15 has a crimpfold 34 in its center area, which balances out longitudinal changescaused by heat.

It is further shown that the connector plate 15 for seating the pressurepiece plates 26 has a protuberance 28 in each case, which is providedwith a closed bottom section, in which the facing terminal front area ofthe pressure piece plate 26 is embedded.

This protuberance 28 has radially arranged stop notches 29, which on aninside, due to the given shape, form a catch groove, into which noses 31of the adjustment element 9 engage, whereby the stated securing oftorsion-resistance is produced.

In the end area of the adjustment elements 9, 10 that faces theprotuberance 28, radially extending slots 32 are provided on the surfacearea, which slots form both a heat insulation and breakthroughs 33,which are provided at a thereto formed collar 35 of the pressure piece11, and which extend radially.

FIG. 7 shows that the end area of the pressure piece 11 embedded in theprotuberance has an undercut 36 on its side surface. For axially fixingthe pressure piece 11, a pressure piece plate 26 is pressed onto theprotuberance 28, by means of which the surface area of the protuberance28 is pressed into the undercut 36 of the adjustment element 9, whereina corresponding formation of the pressure piece plate 26 rests againstthe surface of the protuberance 28 in this section.

The pressure piece plate 26 consists of radially extending recesses 27,which also serve as heat insulation, or an interruption of the heattransmission.

In the side walls of a center opening 37 of the pressure piece plate 26,catch grooves 30 are arranged, which correspond to the stop notches 29of the protuberance 28, thereby securing the pressure piece plate 26against torsion.

FIG. 7 shows that the heat-insulating layer 13 is attached onto thecircular area of the pressure piece plate 26, namely on the side thatfaces the brake lining 3, 4.

FIG. 8 makes clear that at the pressure piece 11, 12, or at anothercomponent at the adjustment element 9,10, on both sides of the brakedisc 2, one or more plate springs 42 are joined, each undercutting a rod43 in a recess 44 of the lining support. Thereby the pressure pieces 11,12 are respectively connected to the lining support plates 3 b, 4 b insuch a way that a retraction of the brake linings 3, 4 is guaranteedwhen the adjustment elements 9, 10 are turned back, and when the brakeis released. The arrangement may also be reversed, i.e., so that thespring is formed onto the lining support plate, and engages into arecess at the adjustment element 9,10, or pressure piece 11, 12. Theprinciple from FIG. 8 may also be utilized in the modifications in FIGS.1 through 7.

1-22. (canceled)
 23. A disc brake having a brake disc, for a commercialvehicle, operated pneumatically or by an electric motor, the disc brakecomprising: a caliper which, in use, straddles the brake disc; a brakeapplication unit arranged in the caliper for applying a braking force;at least one adjustment device arranged in the caliper for offsetting atleast one of brake lining and brake disc wear, said at least oneadjustment device comprising two axially displaceable adjustmentelements, each of which has a respective pressure piece; a commonconnector plate in which end areas of the two adjustment elements whichface a respective brake lining are fixed in a torsion resistant manner;and wherein a single or multi-part heat insulation layer is attached, atleast in sections, at at least one of the connector plate and thepressure piece on a side facing the respective brake lining.
 24. Thedisc brake according to claim 23, wherein the connector plate is athermal shield dimensioned such that it largely covers an opening, whichfaces the brake disc, of an installation space in the caliper in whichthe adjustment device is arranged.
 25. The disc brake according to claim23, wherein the heat insulating layer is formed in one or more parts,and is attached directly to the connector plate as a plate.
 26. The discbrake according to claim 23, wherein an adjustment device is arranged inthe caliper on each side of the brake disc.
 27. The disc brake accordingto claim 23, further comprising an electric motor drive operably coupledto the at least one adjustment device.
 28. The disc brake according toclaim 24, further comprising an electric motor drive operably coupled tothe at least one adjustment device.
 29. The disc brake according toclaim 23, further comprising a pressure piece plate which forms thepressure piece and is positioned on the connector plate, the pressurepiece plate bearing the heat insulation layer.
 30. The disc brakeaccording to claim 23, wherein the heat insulation layer is formed of aceramic material.
 31. The disc brake according to claim 29, wherein thepressure piece plate is arranged flush with a surface of the connectorplate and held in an axial and torsion-resistant manner.
 32. The discbrake according to claim 31, wherein the pressure piece plate includesrecesses formed therein in a direction of the connector plate.
 33. Thedisc brake according to claim 23, wherein the connector plate isprovided with protuberances in a connection area with the adjustmentelements facing the brake lining, said adjustment elements being fixedaxially and torsion-resistantly in said connection area.
 34. The discbrake according to claim 33, wherein said protuberances have acylindrical-shape and include stop notches, which stop notches formcatch grooves on an outer surface for the pressure piece plate and on aninner surface form catch grooves corresponding to noses of theadjustment element.
 35. The disc brake according to claim 33, whereinthe area of the adjustment element that extends into the protuberancehas, on a side surface thereof, slots which extend through the material.36. The disc brake according to claim 35, wherein the adjustment elementincludes a peripheral collar that rests against the connector plate. 37.The disc brake according to claim 36, wherein said collar includesbreakthroughs.
 38. The disc brake according to claim 36, wherein anundercut is formed on an end area of the adjustment element that extendsinto the protuberance and which is adjacent the collar, into which saidundercut a correspondingly formed nose of the pressure piece plateengages by pressing into a surface area of the protuberance.
 39. Thedisc brake according to claim 38, wherein the pressure piece plate isformed in a circular shape having a center opening that engages in theundercut of the adjustment element.
 40. The disc brake according toclaim 23, further comprising expansion bellows coupled to the connectorplate and covering the adjustment element at least partially.
 41. Thedisc brake according to claim 40, wherein the expansion bellows isattached, at an end facing the connector plate, to an inner collar atthe pressure element, and to an outer collar at the connector plate. 42.The disc brake according to claim 23, wherein the connector plate has awave fold in a center area extending transverse to a longitudinal extentof the connector plate.
 43. The disc brake according to claim 23,wherein the pressure pieces and lining support plates of the brakelinings are coupled to one another such that a retraction of the brakelining occurs when the adjustment elements are retracted, and when thebrake is released.
 44. The disc brake according to claim 43, furthercomprising one or more plate springs arranged at one of the pressurepiece or a component of the adjustment element, said one or more platesprings undercutting a rod in a recess of the lining support plate. 45.The disc brake according to claim 43, wherein at the lining supportplate one or more plate springs are arranged, which plate springsundercut the pressure piece or a component of the adjustment elementcoupled to the pressure piece.